Question

Java programming

Write a method that recursively calculates the sum of digits for an integer.

121 would be 1 + 2 + 1 which is 4.

Hint: %10 would give you the final digit.

Answer 1

import java.util.Scanner;

public class SumOfDigits {

    public static int sumOfDigits(int n) {
        if (n < 0)
            return sumOfDigits(-1 * n);
        else if (n == 0)
            return 0;
        else
            return (n % 10) + sumOfDigits(n / 10);
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        System.out.print("Enter an integer: ");
        int n = in.nextInt();
        System.out.println("Sum of digits of " + n + " is " + sumOfDigits(n));
    }
}